Just how green are electric cars?

Demand for electric vehicles (EVs) is growing rapidly. In 2018 there is estimated to be over 160,000 of them in the UK, and it’s predicted that by 2040, 55% of all new car sales worldwide will be EVs. With Tesla leading the way in the electric car realm – with the Model 3 to be released in 2019 – other car manufacturers are swiftly following suit. Jaguar, for instance, released their first electric car this year, the I-Pace.

With the practical drawback of range being a major factor in the EV’s slow climb to popularity, advancements in battery technology are beginning to put this issue to rest. Jaguar’s I-Pace can travel almost 300 miles between charges, making it a much more feasible option than electric cars of a few years ago. It looks like there’ll be more of this to come too, as Jaguar have pledged to stop manufacturing cars that are solely powered by internal combustion engines by 2020. This decision, and a similar one made by Volvo, may have been prompted by pressures from governments (including British and French) who have committed to ban the sale of petrol and diesel cars by 2040.

For these reasons, within the next 20 years we could see an explosion of EVs on our roads as they become our green transport solution. And why shouldn’t they? A zero-carbon emission vehicle sounds like the perfect answer to climate change and air pollution problems. But this story may not be as simple as it first appears.

The pitfalls of electric vehicles

It’s true that fully-electric vehicles emit no tailpipe pollutants, but unless you can charge your car from a renewable supply it will be charged from the national grid, which isn’t 100% green. What’s more, the manufacturing process uses large quantities of electricity and water, sometimes even in excess of the levels needed for non-electric vehicles, due to the battery production. Batteries pose other problems too. Rare metals such as cobalt are required for their construction, and these can be very inefficient to mine. Then there’s the question of how we should dispose of old batteries.

Are there better alternatives?

Many alternative power sources have been explored including engine air compressors, biofuel, ammonia, formic acid, liquid nitrogen and hydrogen fuelled vehicles, each of which has their own drawbacks. Hydrogen vehicles are perhaps seen as the main contender to EVs and have received a great deal of attention and funding in recent years. However, they have also been widely criticised for being one of the least efficient, most expensive ways of reducing greenhouse gases. It may even be that they are a distraction from the more readily available solutions to reducing fossil fuels in vehicles, such as EVs. Currently, humankind is unable to produce 100% carbon-free transport, but electric vehicles are a metaphorical mile ahead of any alternatives in terms of being a realistic solution to our transport needs.

Is electricity cleaner than petrol or diesel?

Charging your car directly from the national grid may not be as bad as it sounds. It’s not as if you’re getting your energy directly from a coal power plant after all. Your car will actually be charged from the mix of energies that make up the national grid’s power supply, of which coal is only a very small percent. The energy mix of the British national grid is roughly this: 40% natural gas, 30% renewables, 21% nuclear, 7% coal and 2% other. So, almost a third of this mix is renewable energy – with the percentage set only to increase – and a large proportion is natural gas. Despite being a fossil fuel, natural gas actually produces more energy per carbon emission than either petrol or diesel, making it a lesser pollutant. So charging your vehicle from a mains power supply, although not entirely green, is still cleaner than pumping it full of petrol or diesel (and it’s cheaper too). There are also ways to make your car’s energy greener. You can opt for a fully renewable energy tariff at home, and you can find renewable car charge points.

Is battery manufacturing a problem?

Another problem with electric vehicles is the quantity of resources it takes to manufacture their batteries. But instead of looking at the emissions produced during their production, we must instead consider the total emissions of an electric vehicle from cradle to grave. One study has found that “electric cars emit significantly less greenhouse gases over their lifetimes than diesel engines, even when they are powered by the most carbon intensive energy.” The study went on further to explain that as more renewables enter the grid, and battery technology improves, emissions from their production could be cut by as much as 65%.

What should we do with old batteries?

Finally, with an increase in electric vehicles hitting the road, an effective battery recycling solution will be called for. One option is to use old car batteries as energy storage in the home. They will be cheaper than brand-new batteries, but they will still have ample capacity for household use. Alternatively, batteries will need to be recycled. A small number of companies have the technology to do this today, but Tesla have pledged to improve their battery recycling capabilities to meet future demands for this service. Today they are working with Umicore, in Europe, to recycle their battery packs. Tesla states that: “the Umicore battery recycling technology is able to save at least 70 percent on CO2 emissions at the recovery and refining of these valuable metals.”

SunGift’s electric fleet

At SunGift we understand the importance of electric vehicles in the fight against climate change, so we are making the transition to a fully electric fleet of vehicles. To aid this changeover, we have recently installed 3 new electric charging ports at our office that power our cars with the solar energy we produce. We now have 4 charge points to power our 4 plug-in electric vehicles.

It looks as if electric vehicles could be one of our best shots at a green transport solution. The technology is still in its infancy and has a way to go in making it a truly viable option for the future, but an increasing demand for electric vehicles will put pressure on manufacturers to advance the technology further still.

Comments

One issue not touched upon is safety. Lithium Ion batteries when punctured can and often do ignite very easily. How’s that more of a problem than burning petrol? Well they are very difficult to put out, remember at school burning magnesium? Well this is very similar very hot burn and self-fuelling. Remember the Dreamliner being grounded? That was because the halon gas extinguishers can’t cope with the fire. Richard Hammond found this out and ended up in hospital. My nephew in the states is a fire fighter and has been trained that unless there is danger to life not to tackle any electric vehicle fires, resulting in total write offs for what would be even quite minor incidents. The majority of incidents involve road debris puncturing the cells.

When Lithium Ion burns the main gas given off is carbon dioxide, quite harmless to humans. However other chemicals used in the batteries will give off highly toxic gasses that even minor inhalation will cause raspatory injury requiring emergency medical attention. This is apart from the fact that if you are unable to get out of an EV you will be pretty much cremated.

Over 90% of Lead Acid batteries are recycled. Just under 5% of Lithium based ones are. Much of the UK's Lithium battery waste goes to Belgium where it is incinerated.

Household recycling is still a grey area in the UK - even the councils don't know fully where it really ends up. Often shipped abroad to Bangladesh or elsewhere: out of westener's sight, out of westerner's mind.

Have a spare 94Ah BMW i3 battery pack but getting it re-used either by upgrading older car or retrofitting into energy storage can be a minefield.

Tesla have not approved any of their packs for re-use. Renault and Nissan have looked into it. BMW and others sell NEW packs for "energy storage".

I have 17 REC PV panels 4.3 KWp and it never really makes enough to fill a 60Ah BMW i3 battery in summer let alone winter. The main reaon for PV was the household consumption. Charging an EV is still robbing Peter to pay Paul. Every little helps but don't expect UK sun to suffice.

Here is a very biased and unfounded statement: "However, they have also been widely criticised for being one of the least efficient, most expensive ways of reducing greenhouse gases. It may even be that they are a distraction from the more readily available solutions to reducing fossil fuels in vehicles, such as EVs. "

Time to consider that both H2 and Electricity are not free but energy tranfer agents. They have to be made using energy and resources. They have to be stored.

You should read about Riversimple - a proper H2EV that is far greener than my BMW i3 (lightest of all EVs).

And it takes just 3 mins to fill up. Ro achieve that with a 100 kWh degradable battery would require a very very rapid charger with associat3ed infrastructrure and energy costs.

Sadly at the end of the day, the IPACE is a very heavy, high drag SUV. Weight means more road contact = more PMs and more pothole inducing wear and tear. Anything above 100 mile real world range means carrying a heavy battery pack. This mean vehilce efficiency (as oppossed to power train efficiency reduces). Think of it like an aeroplane: payload range is key. The more battery size and weight the less capacity to carry people and goods over a reasonable distance.

60% of the world's cobalt is mined in DRC where voer 40,000 kids and far more adults suffer from the dust and the rain forests get deforested. Lithium is more abundant but still uses huge amounts of land and water.

Gordon Murray (F1 designer and engineer) calculated just making and deliviering a normal ICE SUV uses as much energy and pollutes as much as building, delivering and driving a small petrol hatchback 60,000 miles.

So making a new EV is not more environmentally friendly than running an old efficient ICE car - especially if like Finland it runs on renewable HVO made from waste.

Our BMW i3 BEV uses as much energy as our old Audi A2 1,2 tdi which can run on HVO for even less consumption (and lower pollution) than the already amazing 2.4 litres/100km it is still capable of after 1/4 million miles.

There is no issue with varying the rate at which you charge your car although the protocol has a lower limit of 1.4kW. So if your 10kWh/day excess is likely to be significantly reduced if you only want to charge your car from solar.

The pragmatic solution is to charge it with a mix of PV and overhight cheap rate electricity.

There is a charger available from myenergi.uk (zappi) which will allow you to set your preferences -fast (just charge it now) -eco (charge at the lowest rate unless you are exporting electricity, in which case ramp up the car charging) and -eco+(only charge the car when you are exporting electricity). Additionally there are settings which allow you to combine this with your overnight cheap rate power. They even support a sensing circuit so if you have a switched o/p from your meter that only goes live during off peak you can time the charging based on that - so you don't have to worry about the vaugaries of your E7 meter's clock/BST etc... Of course you can do some of this yourself manually by fiddling with the car's maximum charge rate and timing but unles you have no other life it gets old so quickly trying to predict whether the clouds will roll away or not.

BUT - as you point out, in the UK, with a 4kWp PV setup and an average household base load you're not going to get many miles in the summer and probably bugger all in the winter.

I have a 10kWp system and my wife's daily commute is ~40 miles. I prioritise the house battery first (PW II) and when that is full I charge her car and if it isn't full by the start of the off-peak rate I use up what's remaining in the battery then switch to using E7. We have had a grand summer for PV so we have imported trivial amounts to charge the cars for the last few months but January saw 65% of the car charge from E7.

So the answer is

1) No damage varying the car's charging rate - they even do it themselves in response to battery temperature and SoC (charge levelling)

2) Yes you will not get much from your 4kWp PV (depending on your other loads) but it's better than nothing - especially if you have a deemed export FiT.